*: use new slice to array conversion syntax

Closes cockroachdb#110261.

This commit adopts the new slice to array conversion syntax introduced
in go 1.20. The new syntax is only applicable in one small part of the
codebase, so it's a small change.

From https://tip.golang.org/doc/go1.20:

> Go 1.20 extends this to allow conversions from a slice to an array:
> given a slice x, [4]byte(x) can now be written instead of
> *(*[4]byte)(x).

Release note: None

Author: nvanbenschoten

pkg/util/tracing/span.go

@@ -949,8 +949,8 @@ func SpanMetaFromProto(info tracingpb.TraceInfo) SpanMeta {
 		// NOTE: The ugly starry expressions below can be simplified once/if direct
 		// conversions from slices to arrays gets adopted:
 		// https://github.com/golang/go/issues/46505
-		traceID := *(*[16]byte)(info.Otel.TraceID)
-		spanID := *(*[8]byte)(info.Otel.SpanID)
+		traceID := [16]byte(info.Otel.TraceID)
+		spanID := [8]byte(info.Otel.SpanID)
 		otelCtx = otelCtx.WithRemote(true).WithTraceID(traceID).WithSpanID(spanID)
 	}